Anorexia nervosa (AN) is an eating disorder affecting mostly young people which could lead to serious complications and consequences. There are ethnical and gender differences in the incidence and prevalence of AN, but the influence of urbanization has not yet been proved. The relationship of genetic background to the risk of AN is still being investigated. In this review we summarize current knowledge about the relationship between AN and polymorphism of substances known to be regulating eating behaviour or metabolic pathways e.g. serotonin, ghrelin, catechol-O-methyl transferase, neuropeptide Y, brain-derived neurotrophic factor and adipokines.